Dental tool.



C. C. BALL.

DENTAL TOOL.

APPLICATION FILED APR. I. 1915.

1,147,594., Patented my 2o, 1915.

CALVIN C. BALI, 0F HUNTINGTON, WESiT VIRGINIA.

DENTAL 'JJoonl To all whomz'tl-may concern.' i. y

Beit known that I, CALVIN C. BALL, a

citizen of the United States, and resident which is drawn between theteeth over the.

filling to, be finished, the strip being held in place against thefilling by the thumb and finger, a method which being objectionable forobvious reasons, is also objectionable in that the operator cannotseethe filliiig being operated on since it is neces 3 is a section onthe line 3-3 of Fig. 2.

sarily covered by the thumb, or finger, and it is impossible at alltimes to accurately` control. the direction of movement of the strip'forslightly more pressure on one edge of the strip than on the other willcause it to deviate from the desired direction and result either ininjurious contact of the strip with the gum (when no separator is used)or to have such contact with vthe filling as to cut it away. L

The object of my invention is to provide an instrument which willobviate the objections noted and which will haveother advantages, suchas the utilization of power, as from the dental engine to impart themovement to the finishing strip with consequent greater speed in theperformance of the operation, and convenience and comfort to theoperator.

In the accompanying 'drawings-Figure 1 is a perspective view of a dentalinstrur'nent constructed in accordance with my invention; Fig. 2 isaview'partly in side elevation and partly in vertical section; Fig.

Briefly described, my invention in the form which I now regard as itsbest embodiment, comprehends the use of a continuous,

or endless band of such material, as metal, cloth, celluloid, or paperofwhich finishing strips are ordinarily made, which is carried over andsupported by suitably arranged guides in the form of wheels, or pulleysto Specification of Letters Patent. Application filed- April 1, 1915.Serial No. 181,562.

Patented July 2o, 1915.

lone of which motion is imparted by suitable driving connections with',the dental engine,

= and thereby the desired movement imparted y to the finishing strip. v

Referring in detail'to theV structure lshown in the accompanyingdrawings, it will be found that la casing head l0 is employed onV theoutside of whichat': one side is' located vthe driving pulley 11 andfrom which'project two larms 12 that preferably diverge from each other,each of which at its outer l Vend supports a guide pulley 13. Over the.three pulleys is placed a continuous, or endless band 14 thatconstitutes the l'finishing strip, which band, as I have indicated, maybe of any desiredmaterial suitable for the purpose and having such widthand thinness as may be required. v It will thus be seen thatthefinishing stripis supported by an open frame and the twopulley-cairying arms are mounted for movement toward and from each otheras by being made of spring material, their normal position being the onewhere their pulleys are most widely separated. The portion of thefinishing strip extending between the two pulleys 13 is the portion thatis applied to the filling and by reason of the capability of thepulley-carrying arms to move toward each other it will be seen that bypulling against thefilling such portion of the strip will be changedfrom lts straight direction and caused to conform to a rounded surfaceand thereby give a convexly rounded conforma*- tion to the fillin Theflexibility which the spring arms a ord is also important infacilitating the application of the finishing strip to the tooth fillingto be operated upon and also lin facilitating 'the changing o the stripswhen that is required. The -tension placed upon the strip by the springtendency of the arms at all times maintains the strip in the tautposition necessary to cause its movement by the driving action of lthepulley 11.

. In order to compensate for differences in /the length of strips, oneof the pulley-carrying arms is adjustable toward and from the other asby means of a thumb screw 15 which passes through an opening in the armand enters a threaded opening in the side of the casing head 10, the armbeing pivoted, or fulcrumed betweenV such thumb screw and the pulley, asby means oft' a fastening screw 16, so that according-to the portantfunction of a rest for the end of the thumb of the operator when holdingthe'instrument, the outer face of said thumb screw being dished, orconcave and serrated or `roughened so as to afford a comfortable andfirm bearing for the operators thumb when holding the instrument bymeans of the shank, or handle with `which it is provided and to theouter end of which-the casing head 10 is attached, all as moreparticularly hereinafter described.

In order' to increase thel angle of peripheral contact of the nishingstrip with the driving pulley, an idler pulley, or guide roller 17 ismounted on the top of the casing head well to. one side of themiddistance between the pulley-carrying arms Where they extend outwardfrom said head, so that the portion of the finishing strip passing fr omthe driving pulley to one of the guiding pulleys 13 insteadl ofextending tangentially from the driving pulley to said guiding pulley13, it is carried over the driving pulley fairly close to the portion of the strip running tangentially from the driving pulley to the otherdriving pulley 11.

The driving pulley 11 is in the lform of a sleeve which is journaled ona stud 19 that projects from the inside of one of the side walls of thecasing head and Within the casing on said sleeve is a bevel gear 20 withwhichimeshes a bevel pinion 21 upon the upper end of a shaft 22 Whichextends through the shank 23, and a detachable connecting piece 24 forcoupling the instrument to the engine hand piece and for connecting saidshaft with the engine shaft. The connection between the connecting pieceand the'shank is a threaded detachable one so that bychanging theconnecting piece according to the engine hand piece my instrument isrendered universal, or adaptable to dental engines generally.

ln order to increase the, friction of the driving pulley upon thefinishing strip, the strip-engaging surface of the pulley may be formedof rubber, or other suitable material. The pulley has a flange formed bya disk 25 which is secured` by a screw tothe outer end of the pulleyjournaling stud. rlhe stud is made tubular, or hollow throughout itslength to form in rear of the screw an oil chamber from which oil maypass outward and find its way between the pulley sleeve and the exteriorof the stud for 1ubricating purposes. Each of the strip guide pulleys 13is similarly in the form of a tube orsleeve upon a hollow, or tubularstud that projects from the carrying arm, so that -similar provision forlubricating is pfvided.

For convenient access to the interior of the casing head, one sidethereof, to which may be integrally attached the top, is removablysecured by screws, and for oiling the rotating parts within the casinghead, an oil hole having a suitable cover may be provided.

While the-construction illustrated in the drawings is a very desirableembodiment of my invention, it is to be understood that my invention isnot restricted in its broad scope to any one construction andarrangement of the parts.

Having thus described my invention what I claim is- 1. As an improvementin dental instruments, the combination of ahead, a driving pulleymounted on said head, a pair of arms projecting from the head, a workingstrip in the form of a contin'uous band passing over said pulley andover oppositely situated supports on said arms, and means for revolvingsaid driving pulley to impart movement to said strip.

2. As an improvement in dental instruments, the combination of a movablysupported finishing strip in the form of a continuous traveling band,the supporting means comprising a frame' having members movable towardiand from each other, and means to impart movement to said sti'ip tocause it to travel With reference to said frame.

3. As an improvement in dental instruments, the combination of a movablysupported finishing strip in the form of a continuous traveling band,the support comp'ising a pair of spring arms, and means toimpartemovement to said strip to cause it to travel with referenceto'said frame.

4. As an improvement in dental instruments, the combination of a head, amovably supported finishingv strip, said supporting means comprisinganarm mounted t0 rock on said head, an adjusting device for said arm thatforms a thumb rest, and means to impart movement to said strip.

5. As an improvement in dental instruments, the combination of a casinghead,.a pair of spring arms extending therefrom, each carrying a pulley,a driving pulley mounted on the casing head, a finishing strip extendingover said pulleys, and gearing for revolving said driving pulley mountedin the casing head.

6. As an improvement in dental instruments, the combination of a casinghead, a pair of spring arms extending therefrom, each carrying a pulley,a driving pulley mounted on the casing head, a finishing strip extendingover said pulleys, gearing for revolving said driving pulley mounted inthe casing head, and a shank for said casing head including a detachableengine-connecting piece.

7. As an improvement in dental instruments, the combination of a casinghead, a strip from the driVing pulley to one of the pair of spring armsextending therefrom, arm-supported pulleys. 10 each carrying a pulley, adriving pulley In testimony that I claim the foregoing mounted on thecasing head, a nishing I have hereunto set my hand.

strip extending over said pulleys, gearing CALVIN C. BALL. for revolvingsaid driving pulley mounted Witnesses: in the casing head, and a'guidefor the CHAs. E. BOOTH,

finishing strip to change the direction of the LEVEZEY.

